1. Field of the Invention
The invention relates to an inkjet recording apparatus.
2. Description of Related Art
So far, what is known as an inkjet recording apparatus is, for example, an apparatus comprising a recording head for jetting ink toward a recording medium, a plurality of ink cartridges each of which comprises the recording head and an ink pool unit for pooling ink to be supplied to the recording head, a carriage which contains the plurality of ink cartridges and which moves back and forth along a main scanning direction over the recording medium, an ink residual quantity detecting section for detecting that ink residual quantity pooled in the ink pool unit of an ink cartridge being used becomes zero or not more than predetermined quantity, an ink cartridge switching section for switching the ink cartridge to new one when the ink residual quantity detecting section detects that ink residual quantity of the ink cartridge becomes zero or not more than the predetermined quantity, and the like (for example, see Japanese Patent No. 3131964).
Further, what is also known is an inkjet recording apparatus comprising a plurality of ink cartridges for pooling ink of the same color, wherein ink residual quantity within each ink cartridge is detected with a provided residual quantity detecting sensor with each ink cartridge, and with a switching section switching an ink cartridge to be used, it is possible to prevent from stopping a recording operation (for example, Japanese Patent Application Publication (Unexamined) No. Tokukai 2002-29041).
By the way, since an ink cartridge is contained in a carriage in the inkjet recording apparatus of the above-mentioned structure, in order to switch the ink cartridge during a recording operation, it is necessary to stop the printing temporarily. Therefore, an inkjet recording apparatus capable of switching an ink cartridge without stopping a printing during a printing operation by providing an ink cartridge and a carriage individually, has been developed (for example, see Japanese Patent Application Publication (Unexamined) No. Tokukaihei 4-10954).
However, although it is possible to switch an ink cartridge without stopping the printing during a recording operation with the ink cartridge and a carriage provided individually as the mentioned way, since there are some ink cartridges of which it is not possible to confirm residual quantity of ink based on its appearance, there is a possibility of loading an empty ink cartridge by mistake. If an empty ink cartridge is loaded, when an ink cartridge which is currently being used becomes empty and the ink supply source is switched to the loaded ink cartridge, ink is not supplied to the recording head and thereby a printing has to be stopped.
Further, with a structure in which each of the plurality of ink cartridges comprises a residual quantity detecting sensor, since it is necessary to have a large number of expensive residual quantity detecting sensors, it is costwise inefficient.